Alzheimer’s blocked in mice by gene deletion

Scientists have identified a gene that when deleted can prevent the build up of the toxic plaques that are the hallmark of Alzheimer’s disease. The findings are based on observations from human brain samples that were investigated using a mouse model of the disease.

Genetic profiling of biopsy brain samples found that the gene encoding an enzyme called Jnk3 is unusually active in the brains of patients who have died of Alzheimer’s Disease. To investigate the role of Jnk3 the researchers turned to an animal model of the disease – a mouse that accumulates the same brain plaques and suffers loss of memory as do people with the neurological disorder.

By using the mouse, they were able to delete the Jnk3 gene entirely. Mice without Jnk3 produced 90% less amyloid-beta – the protein that forms the brain plaques – than untreated mice. Memory function was also significantly improved to levels similar to that of healthy mice.

Further experiments found that Jnk3 is an enzyme that affects proteins controlling the production of amyloid-beta. In Alzheimer’s patients, Jnk3 appears to over-stimulate production of the plaque-forming protein leading to its accumulation in neurons. Future work will focus on developing medicines that can control the activity of Jnk3.